An analysis of Bitcoin OP_RETURN metadata
This study addresses concerns in the Bitcoin community about how OP_RETURN metadata might affect network performance, providing data-driven insights for stakeholders.
The paper empirically analyzed the usage of Bitcoin's OP_RETURN feature over time, identifying and classifying protocols by application domain, and measuring their evolution, distribution, and space consumption.
The Bitcoin protocol allows to save arbitrary data on the blockchain through a special instruction of the scripting language, called OP_RETURN. A growing number of protocols exploit this feature to extend the range of applications of the Bitcoin blockchain beyond transfer of currency. A point of debate in the Bitcoin community is whether loading data through OP_RETURN can negatively affect the performance of the Bitcoin network with respect to its primary goal. This paper is an empirical study of the usage of OP_RETURN over the years. We identify several protocols based on OP_RETURN, which we classify by their application domain. We measure the evolution in time of the usage of each protocol, the distribution of OP_RETURN transactions by application domain, and their space consumption.